THE EFFECT OF COLD STORAGE OF POTTED AZALEA ON BROAD MITE INFECTION

Area of Science:

• Horticultural Entomology
• Plant Pathology
• Integrated Pest Management

Background:

• Broad mite (Polyphagotarsonemus latus) poses a significant economic threat to potted azaleas (Rhododendron simsii hybrids).
• Limited chemical control options and acaricide application restrictions necessitate alternative pest management strategies for growers.
• Prior research suggests broad mite survival and reproduction are severely inhibited below 7°C.

Purpose of the Study:

• To experimentally verify and quantify the efficacy of cold storage as a control method against broad mites on azalea plants.
• To assess the impact of cold storage duration on broad mite population reduction and reproductive capacity.

Main Methods:

• Azalea plants were artificially infested with broad mites.
• Plants were subjected to cold storage at 3°C for durations of 2, 3, or 4 weeks.
• Post-storage, plants were moved to a heated greenhouse for 2 weeks to evaluate mite survival and reproduction.
• Broad mite populations were quantified before cold treatment, immediately after, and two weeks post-treatment.

Main Results:

• Cold storage significantly reduced broad mite populations by up to 90% immediately following treatment.
• A 4-week cold treatment demonstrated an additional suppressive effect on broad mite reproduction.
• A further decline in mite numbers was observed after transferring plants to a heated greenhouse, indicating reduced reproductive capacity.

Conclusions:

• Cold storage of azalea plants at a maximum of 3°C for at least 4 weeks is a viable alternative control method for broad mites.
• This method offers a significant reduction in pest populations and can impact reproductive success.
• Cold storage should be considered an integrated component of broad mite management in the final stages of azalea production.